Respiratory Syncytial Virus Infections within Families

TLDR

The study examined intrafamily spread of respiratory syncytial virus and associated illnesses in 36 families comprising 188 members during an outbreak. Nurses conducted specimen collection and household interviews every three to four days to isolate the virus. The virus infected 44.4 % of families and 21.9 % of all members, with secondary attack rates of 27 % overall and 45.4 % in infants, and 94.9 % of cases had acute respiratory illness that was more severe than non‑RSV illnesses.

Abstract

To examine intrafamily spread of respiratory syncytial virus infections and their associated illnesses, 36 families with 188 members were studied during an outbreak of such infections. Nurses visited every three to four days to obtain specimens for viral isolation and interview household members. The virus infected 44.4 per cent of families, and 21.9 per cent of all members. All age groups had appreciable attack rates (with a range of 16.8 per cent in adults to 29.4 per cent in infants). In infected families, 45.9 per cent of members became infected, including 10 of 16 infants. Secondary attack rate for all ages was 27 per cent, and that for infants 45.4 per cent. An infant's older sibling appeared most likely to introduce the virus into the family. Associated acute respiratory illnesses occurred in 94.9 per cent of cases, and appeared more severe than those not associated with respiratory syncytial virus. When the virus was introduced into a family the high attack rate produced an illness of age-related severity.